Insulation



Patented Aug. 13, 1929.

UNITED STATES PATENT OFFICE.

BRUNO E. BAIIDUF, OF CHICAGO, ILLINOIS, ASSIGrNOR 'JIO UNITED STATES; GYPSUM COMPANY, CHICAGO, ILLINOIS, A. CORPORATION OF ILLINOIS.

INSULATION.

No Drawing.

This invention relates to a new, fluffy, dry, powdered insulating agent having fire resistive,'sound absorbing, and other novel features not found in ordinary )owdered insulating agents. Among the o jects ofthe invention are; to provide a new insulating material which is easily handled as a dry filling agent; to utilize materials formerly regarded as waste products in producinga Tltl new commercial article; to provide an insulating material which is variable in weight depending upon the ingredients used, which is flufi'y and light in appearance, but which will not be packed down or compressed by to the weight of a column of such material; to provide an elastic material of this kind which will not slump down or sift away, but remains piled. Vertically; to utilize such ingredients that the material although light and ac fiufty in appearance can be spread out in a thin layer and sprinkled lightly with water or other liquid thereby forming a light crust on top of the material to prevent it from being blown about; to provide a light, flutly, We elastic insulating material of this kind which can be made, used and applied as hereinafter set forth; and in general to provide a new material of this kind as hereinafter set forth.

Gypsum in its various forms, hydrous, partially hydrous, or anyhydrite, has'long been known and used as a fire resistive insulating agent, especially as contrasted with the low insulation properties of Portland 5 cement, ordinary masonry, or similar fire resistivc masonry materials. In ordinary materials the insulating properties and sound absorbing qualities cannot be built up to a high standard Without materially sacrificing the fire resisting properties, but on account of the high fire resistance of gypsum, it is possible materially to build up its insulating properties by incorporating with it some fibrous material which will retain its fibrous 45 structure through extremely fine grinding with gypsum. Thus by making a mixture of coarse gypsum and this fibrous agent, and comminuting the mixture to extreme finemess with suitable machinery, the resulting fill powder becomes fibrous and flufiy taking on the joint characteristics of the union.

Hydrous gypsum may be extended into organic fibrous material by such grinding,

with the result that up to or of Application filed May 8, 1926. Serial No. 107,797

fibrous organic material can beincm'poratcd with the gypsum during this line comminution and the resultant powder still will not support combustion.

This new insulating agent is a mixture of calcium sulphate, which is more or less hydrated, ground paper pulp, paper stock, or other vegetable or mineral fibres which can be ground and intimately mixed with gypsum during grinding to develop light weights per cubic foot. It properly made, this powdered insulating agent is of fine fibrous nature, very elastic in structure so that it is not easily compressed by weight. Thus it will remain lightly packed when placed between walls or other structures which it is desired to insulate and does not pack down or together with age, or settle, thereby lowering its insulation efiiciency. In addition this fibrous, fiuffy powder does not run, fall, or break off easily from a mass of the material,

.but remains piled vertically with scarcely any slumping or sifting, all due to its elastic and fibrous nature. A

Furthermore this new product has the very advantageous property that when spread or placed in a thin layer, or in a layer several inches thick, as between joists over the plaster on top of a plastered ceiling, ap plied for example in a floorless attic, it can be lightly sprayed or sprinkled with water from a sprinkling can and a thin crust will be formed on the surface of the insulating material when this light water has dried.

This crust is quite tenacious and is a prop erty directly of the peculiar light, fibrous construction of the insulation and also of the gypsum which is the major ingredient. Thus when subject to sudden air blasts from open windows or the like the material will not dust or be blown around when this crust has been formed on it.

In addition this new insulating agent can be applied directly back or between lath crevices with no paper needed to hold it in place back of the lath. It is so fibrous and elastic in its-clinging nature that no flowing occurs between the lath spaces.

In one method of manufacture of this new insulating agent, calcined gypsum which has been rehydrated with Water is used, in the form of gypsum block, tiles, gypsum boards, and the factory wastes resulting from these productions. If these products are not 'with some addition of calcined when lightly packed in place,

available ground-gypsum rock can be used gypsum, mixed together until a hardened mass results. These products from whatever source prepared, are dried, then beaten up well in a hammer mill or a similar type of disintegrator. When this material is beaten up,

the re uired amount of shredded paper stock may t en be added so that the mixture can be further shredded, or the paper may be shredded separately and mixed in later. After the paper and gypsum have been shredded and mixed together this coarser granulated product is reground by special grinding mills like feed mills, which give it a fine cutting action as well as a fine powdering action during this final grinding operation. The resultant powder is quite homogeneous, very elastic, and a fine fibrous product in which the different constituents are perfectly blended. Because of this homogeneous structure and high content of gypsum, the product is very fire resistive and will not support. combustion.

In a product intended as a very efficient insulator, weighing approximately twelve pounds per cubic foot when lightly packed in place, paper pulp or paper-like chip paper is employed as the fibrous agent in the ratio of one part of fibre to four parts of dried rehydrated calcined gypsum, and this gives a product composed of 80% gypsum and 20' 0 fibrous material; for a product weighing twenty-four pounds per cubic foot one part of brous material is used to seven parts of gypsum, so that the product contains 87%% of gypsum and 12 of fiber.

Plaster wallboard may be used alone or I it may be combined with a small percentage of finely shredded paper. To increase the weight or content of gypsum, ground .gypsum tile alone can be used. In this way any set mixture of fibrous agent and gypsum can be obtained, and are desirable because many types of insulation require different proportions of gypsum and fibres, but in the main it is desirable to limit the fibrous material to 25% or under because of the adresistance in the vantage of having high fire resulting product.

In carrying out this process'the gypsum will be slightly calcined or dehydrated resulting from the use of plasterboards having burned or dehvdrated cut ends, 0 that when the surface or top portion of t e material is sprinkled lightly with water, it will have a light crust or layer on top formed by the hydration of a portlon ofdehydrated gypsum. The advantage of this is apparent when applying the material to the top of the plastered ceiling, as between the rafters in an unfloored attic, the sprinkling of water over the entire top of the materials forming a thin yielding crust which prevents the material from being blown about or sifting through cracks or crevices. This material may also be blown in place as through a hose, for example in covering a ceiling which has a floor above it, the hose 7 being introduced between the floor and the ceiling and the fibrous material dischar ed therefrom. In such case the layer formed may be sprinkled with a thin stream or spray of water which will form the desired crust.

I claim:

1. A dry, fiufi'y insulating composition comprising shredded paper and comminuted plaster in substantially the proportions that these materials exist in a plasterboard having a plaster core and paper covering sheets.

2. A dry, fluffy, composition containing, a mixture of paper fibers and hydrated gypsum, said mixture being the product resulting when gypsum plaster boards and wallboards are comminuted and beingadapted to be poured in a dry state into structures to be insulated.

3. A composition of matter comminuted wallboards having paper covers and hydrated gypsum cores, so that the composition is a light, fluffy mixture of partially hydrated avusum and fibers.

4C. The method of recovering waste plaster board from the gypsum industry which comprises drying the waste boards and comminuting same to form a light, fluffy, insulating mixture having a gypsum to fiber content substantially equal to the gypsum to paper content in the original boards.

5. A dry, flufi'y composition containing a mixture of powdered gypsum and 12 92) to 25% b weight of paper fibers, said CO1 position being adapted to be poured in a dry state into structures to be insulated.

BRUNO E. BALDUF. 

